diff --git a/tests/Composer/Test/Command/RequireCommandTest.php b/tests/Composer/Test/Command/RequireCommandTest.php
index 63662721d..11c1049a5 100644
--- a/tests/Composer/Test/Command/RequireCommandTest.php
+++ b/tests/Composer/Test/Command/RequireCommandTest.php
@@ -19,12 +19,14 @@ use Composer\Command\RequireCommand;
 use Symfony\Component\Console\Input\ArrayInput;
 use Composer\Console\Application;
 use Composer\Test\TestCase;
+use Symfony\Component\Process\Process;
 
 class RequireCommandTest extends TestCase
 {
     /**
      * @var string
      */
+    private $start_directory;
     private $working_directory;
     private $local_repository;
 
@@ -55,6 +57,7 @@ class RequireCommandTest extends TestCase
 
         $manifest = [
             'name' => 'test/something',
+            'require' => (object) null,
             'repositories' => [
                 [
                     'type' => 'path',
@@ -71,17 +74,25 @@ class RequireCommandTest extends TestCase
             json_encode($manifest, JSON_UNESCAPED_SLASHES)
         );
 
+        $this->start_directory = getcwd();
     }
 
     protected function tearDown(): void
     {
         parent::tearDown();
 
+        // Reset the working directory. Some commands leave the working
+        // directory contaminated when they exit with an error.
+        chdir($this->start_directory);
+
         $fs = new Filesystem();
         $fs->removeDirectory($this->working_directory);
         $fs->removeDirectory($this->local_repository);
     }
 
+    /**
+     * testcase: UC01-001
+     */
     public function testInstallPackage(): void
     {
         // Arrange
@@ -89,21 +100,51 @@ class RequireCommandTest extends TestCase
         $application->setAutoExit(false);
         $application->add(new RequireCommand());
 
+        $local_repository_class_code = '<?php namespace TestVendor\\Testpackage { '
+            . 'class TestClass { '
+            . 'public function printTestClass() { echo "TestClass"; } } }';
+        $local_repository_class_file_dir = $this->local_repository . '/src';
+        $local_repository_class_file = $local_repository_class_file_dir . '/TestClass.php';
+
+        mkdir($local_repository_class_file_dir, 0777, true);
+        file_put_contents($local_repository_class_file, $local_repository_class_code);
+
+        $check_autoload_code = 'include "./vendor/autoload.php";'
+            . 'use TestVendor\\Testpackage\\TestClass;'
+            . '(new TestClass())->printTestClass();';
+        $check_autoload_process = new Process(['php', '-r', $check_autoload_code]);
+        $check_autoload_process->setWorkingDirectory($this->working_directory);
+
         // Act
         $tester = new ApplicationTester($application);
         $tester->run([
             'command' => 'require',
+            // Confirmation 1: provide dependency name of format vendor/package
             'packages' => [ 'testvendor/testpackage' ],
             '-d' =>  $this->working_directory,
         ]);
 
+        $check_autoload_process->run();
+
         // Assert
         $output = $tester->getDisplay();
+
+        // Confirmation 4: exit code 0
         $tester->assertCommandIsSuccessful();
+
         $this->assertStringContainsString('Installing testvendor/testpackage', $output);
+
+        // Confirmation 2: dependency is present in vendor directory
         $this->assertTrue(file_exists($this->working_directory . '/vendor/testvendor/testpackage'));
+
+        // Confirmation 3: dependency classes can be autoloaded
+        $this->assertEquals(0, $check_autoload_process->getExitCode());
+        $this->assertEquals('TestClass', $check_autoload_process->getOutput());
     }
 
+    /**
+     * testcase: UC01-002
+     */
     public function testInstallPackageSaveToComposerJson(): void
     {
         // Arrange
@@ -113,6 +154,8 @@ class RequireCommandTest extends TestCase
 
         // Act
         $tester = new ApplicationTester($application);
+
+        // Confirmation 1: Install dependency
         $tester->run([
             'command' => 'require',
             'packages' => [ 'testvendor/testpackage 1.0.0' ],
@@ -124,11 +167,15 @@ class RequireCommandTest extends TestCase
             file_get_contents($this->working_directory . '/composer.json'),
             true
         );
+
+        // Confirmation 2: dependency has been added to composer.json
         $this->assertArrayHasKey('testvendor/testpackage', $manifest['require']);
         $this->assertEquals('1.0.0', $manifest['require']['testvendor/testpackage']);
     }
 
-
+    /**
+     * testcase: UC01-003
+     */
     public function testInstallPackagesSaveToComposerLock(): void
     {
         // Arrange
@@ -161,6 +208,9 @@ class RequireCommandTest extends TestCase
         $this->assertEquals('1.0.0', $installed_package['version']);
     }
 
+    /**
+     * testcase: UC01-004
+     */
     public function testInstallMisspelledPackage(): void
     {
         // Arrange
@@ -196,4 +246,81 @@ class RequireCommandTest extends TestCase
         );
     }
 
+    /**
+     * testcase: UC01-005
+     */
+    public function testInstallNoPackage(): void
+    {
+        // Arrange
+        $application = new Application();
+        $application->setAutoExit(false);
+        $application->add(new RequireCommand());
+
+        // Act
+        $tester = new ApplicationTester($application);
+        $tester->run([
+            'command' => 'require',
+            'packages' => [ '-' ],
+            '-d' =>  $this->working_directory,
+        ]);
+
+        // Assert
+        $this->assertNotEquals(0, $tester->getStatusCode());
+        $output = $tester->getDisplay();
+
+        $this->assertStringContainsString(
+            'Could not find package -.',
+            $output
+        );
+
+        // Assert
+        $manifest = json_decode(
+            file_get_contents($this->working_directory . '/composer.json'),
+            true
+        );
+
+        // Confirmation 2: dependency has not been added to composer.json
+        $this->assertEquals(0, count($manifest['require']));
+    }
+
+    /**
+     * testcase: UC01-006
+     */
+    public function testInstallLongPackageName(): void
+    {
+        // Arrange
+        $application = new Application();
+        $application->setAutoExit(false);
+        $application->add(new RequireCommand());
+
+        $package_name = $this->generateRandomString(8000);
+
+        // Act
+        $tester = new ApplicationTester($application);
+        $tester->run([
+            'command' => 'require',
+            'packages' => [ $package_name ],
+            '-d' =>  $this->working_directory,
+        ]);
+
+        // Assert
+        $this->assertNotEquals(0, $tester->getStatusCode());
+        $output = $tester->getDisplay();
+
+        $this->assertStringContainsString(
+            'Could not find a matching version of package ',
+            $output
+        );
+    }
+
+
+    private function generateRandomString(int $length): string {
+        $characters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
+        $charactersLength = strlen($characters);
+        $randomString = '';
+        for ($i = 0; $i < $length; $i++) {
+            $randomString .= $characters[rand(0, $charactersLength - 1)];
+        }
+        return $randomString;
+    }
 }